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Quantifying commercial catch and effort of monkfish Lophius vomerinus and L. vaillanti off Namibia
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: L. Maartens A. J. BoothAbundance and exploitation patterns of monkfish Lophius vomerinus and L. vaillanti were investigated for use as inputs into a stock assessment framework to be used for management of the Namibian monkfish resource. Total numbers of monkfish caught per size-class were... -
GLM-based standardization of the catch per unit effort series for South African west coast hake, focusing on adjustments for targeting other species
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: J. P. Glazer D. S. ButterworthCatch per unit effort (cpue) data for the South African west coast Cape hakes Merluccius capensis and M. paradoxus were standardized by applying the Generalized Linear Modelling (GLM) technique. The resulting standardized series indicated that resource abundance declined at a... -
AL- and AM-spaces of integrable scalar functions with respect to a Fréchet-valued measure
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Antonio Fernández Francisco NaranjoWe study the question of determining conditions for the space of R-valued integrable functions with respect to a vector measure taking its values in a real Fréchet space to be an AL- or an AM-space. -
Generalized Derivations of Associative Algebras
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Hiroaki Komatsu Atsushi NakajimaIn their paper [6], Leger and Luks introduced the notion of a generalized derivation in nonassociative algebras and got several results for generalized derivations of Lie algebras. This generalized derivation is closely related to Breˇsar's and the second author's generalized... -
The Termwise Equivalence of The Varieties of L-group Cones and Cancellative Generalized Hoops
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: C.J. Van AltenWe show that the varieties of l-group cones and of cancellative generalized hoops are termwise equivalent. We conclude that the varieties of l-groups and cancellative generalized hoops are categorically equivalent. -
Permutation actions of the symmetric group Sn on the Groups Zn m and Zn m
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Jamshid Moori Kenneth ZimbaLet m and n be positive integers. Let Z m = {0, 1, …, m − 1} be the cyclic group of order m and Z n m be the direct product of n copies of Z m . We... -
FISCHER-CLIFFORD MATRICES OF B (2, n)
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Jamshid Moori Kenneth ZimbaIn [3] Almestady has presented a combinatorial method for constructing the Fischer-Clifford matrices of the generalized symmetric groups B(m, n), where m and n are positive integers. As a few examples for small values of m and n show, the... -
(Φ, M)–extensions of near-rings
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Mark FaragIn this paper, we define and study a generalization of matrix, polynomial, and group near-rings. New results on ideal essentiality and lying over are obtained. -
On the Maximal Function for the Generalized Ornstein-uhlenbeck Semigroup.
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Jorge Betancor Liliana Forzani Roberto Scotto WilfredoO. UrbinaIn this note we consider the maximal function for the generalized Ornstein-Uhlenbeck semigroup in R associated with the generalized Hermite polynomials {H μ n } and prove that it is weak type (1,1) with respect to dλ... -
On the Projective Curvature Tensor of Generalized Sasakian-Space-Forms
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: U.C. De --- Department of Pure Mathematics, India Avijit Sarkar --- Department of Mathematics, IndiaThe object of the present paper is to study the nature of generalized Sasakian-space-forms under some conditions regarding projective curvature tensor. All the results obtained in this paper are in the form of necessary and sufficient conditions. -
On Prime and Semiprime Near-Rings with Generalized Derivation
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Öznur Gölbaşi --- Department of Mathematics, TurkeyLet N be a left near-ring and S be a nonempty subset of N. A mapping F from N to N is called commuting on S if [F(x),x] = 0 for all x € S. The mapping F is called... -
Efficient spectral-Petrov-Galerkin methods for third- and fifth-order differential equations using general parameters generalized Jacobi polynomials
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: W.M. Abd-Elhameed --- Department of Mathematics, Faculty of Science, Saudi Arabia E.H. Doha --- Department of Mathematics, Faculty of Science, Giza-Egypt Y.H. Youssri --- Department of Mathematics, Faculty of Science, Giza-EgyptTwo new families of general parameters generalized Jacobi polynomials are introduced. Some efficient and accurate algorithms based on these families are developed and implemented for solving third- and fifth-order differential equations in one variable subject to homogeneous and nonhomogeneous boundary... -
On the metric dimension of generalized Petersen graphs
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Shabbir Ahmad --- Centre for advanced studies in Pure and Applied Mathematics, Pakistan Muhammad Anwar Chaudhry --- Centre for advanced studies in Pure and Applied Mathematics, Pakistan Imran Javaid --- Centre for advanced studies in Pure and Applied Mathematics, Pakistan Muhammad Salman --- Centre for advanced studies in Pure and Applied Mathematics, PakistanA family G of connected graphs is said to be a family with constant metric dimension if its metric dimension is finite and does not depend upon the choice of G in G. In this paper, we study the metric... -
Frame valued stratified generalized convergence groups
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: T.M.G. Ahsanullah Jawaher Al-MufarrijFollowing the notion of stratified L-fuzzy convergence space of Gunther Jäger [Quaest. Math. 24 (2001), 501–517], we introduce the notion of a stratified L-generalized convergence group, and look into some other objects, namely, stratified L-Kent convergence groups, and stratified L-principal... -
Algebraic Entropy of Shift Endomorphisms on Abelian Groups
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Maryam Akhavin --- Faculty of Mathematical Sciences, Iran Dikran Dikranjan --- Dipartimento di Matematica e Informatica, Italy Anna Giordano Bruno --- Dipartimento di Matematica e Informatica, Italy Arezoo Hosseini --- Department of Mathematics, Faculty of Science, Iran Fatemah Ayatollah Zadeh Shirazi --- Faculty of Mathematics, Statistics and Computer Science, College of Science, IranFor every finite-to-one map λ : Γ → Γ and for every abelian group K, the generalized shift σλ of the direct sum ⊕Γ K is the endomorphism defined by (x i ) iεΓ ↦ (x λ(i)) iεΓ [3]... -
Maximal and singular operators in the local “complementary” generalized variable exponent Morrey spaces on unbounded sets
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Canay Aykol --- , Turkey Xayyam A. Badalov --- , Azerbaijan Javanshir J. Hasanov --- , AzerbaijanIn this paper we consider local “complementary” generalized Morrey spaces with variable exponent p(x) and a general function ω(r) defining a Morrey-type norm. We prove the boundedness of the Hardy-Littlewood maximal operator and Calderón-Zygmund singular operators with standard kernel in... -
Development and testing of volume models for Pinus nigra Arn., Fagus sylvatica L., and Quercus pubescens Willd.
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Dimitrios I Raptis --- , Greece Vassiliki Kazana --- , Greece Angelos Kazaklis --- , Greece Christos Stamatiou --- , GreeceVolume models were developed and tested for Pinus nigra Arn., Fagus sylvatica L., and Quercus pubescens Willd. to accurately predict the woody stem volume at tree level, since despite the economic importance of these species in the Mediterranean type of... -
Habitat selection and foraging preference of the endangered addax (Addax nasomaculatus) in a fenced wildlife reserve within its historic range: insights for supporting effective reintroduction
Item type: Journal Article • Journal: African Zoology • Authors: Mohsen Chammem --- , Tunisia Hicham Seri --- , Tunisia Rita Bastos --- , Portugal Mário Santos --- , Portugal Joana Vicente --- , Portugal Touhami Khorchani --- , Tunisia João Alexandre Cabral --- , PortugalReintroduction of species should be based on ecological knowledge, which is fundamental to enhancing the probability of success, but also in predicting the response to future changing landscapes. The addax (Addax nasomaculatus), an endangered antelope whose ecology is mostly unknown,... -
Curvature properties of metric and semi-symmetric linear connections
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Miloš Z. Petrović --- , Serbia Nenad O. Vesić --- , Serbia Milan Lj. Zlatanović --- , SerbiaConsidering a non-symmetric linear connection and its dual one appear 6 independent curvature tensors [15]. In the present paper we study properties of curvature tensors of semi-symmetric metric connections on a generalized Riemannian manifold. -
On some properties of generalized Narayana numbers
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Dmitry Kruchinin --- Tomsk State University of Control Systems and Radioelectronics, Russia Vladimir Kruchinin --- Tomsk State University of Control Systems and Radioelectronics, Russia Yuriy Shablya --- Tomsk State University of Control Systems and Radioelectronics, RussiaIn this paper, we consider a three-parameter generalization of the Narayana numbers that is related to the powers of the generating function for the Narayana numbers. We find a multivariate generating function for these generalized Narayana numbers. For the composition... -
Lie triple centralizers on generalized matrix algebras
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Behrooz Fadaee --- University of Kurdistan, Iran Hoger Ghahramani --- University of Kurdistan, Iran Wu Jing --- Fayetteville State University, USAIn this article, we introduce the notion of Lie triple centralizer as follows. Let be an algebra, and be a linear mapping. We say that ϕ is a Lie triple centralizer whenever for all . Then we characterize the general... -
The W -weighted BT inverse
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: D.E. Ferreyra --- Universidad Nacional de Río Cuarto, Argentina N. Thome --- Instituto Universitario de Matemática Multidisciplinar, Universitat Politècnica de València, Spain C. Torigino --- Universidad Autónoma de Entre Ríos, ArgentinaIn this paper we extend the definition of BT inverse of square complex matrices to rectangular matrices. This new generalized inverse (called the W -weighted BT inverse) always exists and is unique. We investigate several characterizations of the W -weighted... -
Epimorphisms and closure operators of categories of semilattices
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: D. Dikranjan --- Università degli Studi di Udine, Italy A. Giordano Bruno --- Università degli Studi di Udine, Italy N. Zava --- Institute of Science and Technology Austria (ISTA),Motivated by a problem posed in [10], we investigate the closure operators of the category SLatt of join semilattices and its subcategory SLatt O of join semilattices with bottom element. In particular, we show that there are only finitely many... -
Generalized Jordan derivable mappings on
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Kaijia Luo --- Institute of Mathematics, Hangzhou Dianzi University, China Jiankui Li --- School of Mathematics, East China University of Science and Technology, China Shanshan Su --- School of Mathematics, East China University of Science and Technology, ChinaLet be a Hilbert space over the real or complex field and be the algebra of all bounded linear operators on . For arbitrary fixed points C, D, M in , we investigate the structure of linear mappings δ and... -
A Hahn-Jordan decomposition and Riesz-Frechet representation theorem in Riesz spaces
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Anke Kalauch --- Institut für Analysis, FR Mathematik, TU Dresden, Germany Wenchi Kuo --- University of the Witwatersrand, South Africa Bruce A. Watson --- University of the Witwatersrand, South AfricaWe give a Hahn-Jordan decomposition in Riesz spaces which generalizes that of [B.A. Watson, An Andô-Douglas type theorem in Riesz spaces with a conditional expectation, Positivity, 13 (2009), 543–558] and a Riesz-Frechet representation theorem for the T-strong dual, where T... -
On EP matrices, partial isometry matrices and their numerical range
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Gholamreza Aghamollaei --- Shahid Bahonar University of Kerman, Iran Mahdiyeh Mortezaei --- Shahid Bahonar University of Kerman, Iran Mohammad Ali Nourollahi --- , IranIn this paper, some properties of the numerical range of some well-known generalized inverses of matrices, such as Moore-Penrose inverse, Drazin inverse, DMP inverse and CMP inverse, are investigated. In particular, an identification of EP matrices is given via the... -
Double total domination in the generalized lexicographic product of graphs
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Abel Cabrera-Martínez --- Universidad de Córdoba, Spain Ismael Ríos Villamar --- Universidad Autónoma de Guerrero, Mexico Juan M. Rueda-Vázquez --- Universidad de Córdoba, Spain José M. Sigarreta Almira --- Universidad Autónoma de Guerrero, MexicoLet G be a graph of minimum degree at least two. A set D ⊆ V(G) is said to be a double total dominating set of G if |N (v) ∩ D| ≥ 2 for every vertex v ∈ V(G)... -
Generalized derivations with nilpotent values in semiprime rings
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Cheng-Kai Liu --- National Changhua University of Education, TaiwanLet R be a (semi-) prime ring with extended centroid C, let f(X 1, … , Xk ) be a multilinear polynomial over C in k noncommutative indeterminates which is not central-valued on R and let g be a generalized derivation of... -
Cayley regression problem of some groups
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Q. Liao --- Guangdong University of Education, P.R. China W. Liu --- Central South University, P.R. China J. Tang --- Hunan First Normal University, P.R. ChinaIn this paper, we consider the Cayley regression problem of the cyclic groups and the dihedral groups. We give the sufficient and necessary conditions for the cyclic group ℤ n to be a Cayley regression. Moreover, the dihedral group D... -
Adoption and intensity of pearl millet technology packages in drought-prone areas of the Waghimra Zone, Ethiopia: A transition pathway for assuring food security
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Asmiro Abeje Fikadu --- Debre Tabor University, Ethiopia Girma Gezimu Gebre --- Alexander von Humboldt Research Fellow at Leibniz-Centre for Agricultural Landscape Research (ZALF), Germany Hisako Nomura --- , Japan Bishaw Adamtie Takele --- Debre Tabor University, Ethiopia Gedefaw Kindu Wubet --- Debre Tabor University, EthiopiaPearl millet, a climate-resilient crop, is advocated for combating food insecurity in drought-prone areas. To that end, the Ethiopian Agricultural Research Institute and agricultural extensions have been instrumental in promoting pearl millet technology packages. However, a more detailed understanding of... -
On graded-nonnil-Noetherian commutative rings
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Anass Assarrar --- University S.M. Ben Abdellah Fez, Morocco Najib Mahdou --- University S.M. Ben Abdellah Fez, MoroccoOur present work is motivated by several papers which have introduced and studied the notion of nonnil-Noetherian rings. Let A = ⊕ α ∈G A α be a commutative ring with unity graded by an arbitrary commutative monoid G... -
Fractional integral inequalities for s-convex functions in the first sense
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Gültekin Tınaztepe --- Akdeniz University, Turkey Ilknur Yesilce Isik --- Aksaray University, TurkeyCertain fractional integral inequalities via general fractional integral operator are presented for s-convex functions in the first sense. Also, they are restated in terms of the Riemann-Liouville and Hadamard fractional integrals and illustrated. -
The Common Hermitian Solutions of the matrix equations
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On the preservers of some subsets of the approximate point spectrum
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: H. Benbouziane --- Faculty of Sciences DharMahraz Fes, University Sidi Mohammed Ben Abdellah, Morocco M. Ech-Chérif El Kettani --- Faculty of Sciences DharMahraz Fes, University Sidi Mohammed Ben Abdellah, Morocco I. El Khchin --- Faculty of Sciences DharMahraz Fes, University Sidi Mohammed Ben Abdellah, MoroccoLet be an infinite-dimensional complex Banach space and be the algebra of all bounded linear operators on . For , we consider the following spectral sets in approximate point-spectrum, defined by -
Generalized Ƶ-solitons on Perfect Fluid Spacetimes in f(r, T)-Gravity
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Shahroud Azami --- Imam Khomeini International University, Iran Uday Chand De --- University of Calcutta, India Mehdi Jafari --- Payame Noor University, IranThis research paper aims to investigate the properties of almost generalized Ƶ-solitons and almost gradient generalized Ƶ-solitons on perfect fluid spacetimes within f(r, T)-gravity. Initially, we derive some properties of the potential vector field associated with the almost gradient generalized... -
Geometric characterizations of some analytic functions related to the generalized Marcum Q-function
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Abdulaziz Alenazi --- College of Science, Northern Border University, Saudi Arabia Khaled Mehrez --- Kairouan Preparatory Institute for Engineering Studies, University of Kairouan, TunisiaThe aim of this paper is to study certain geometric properties, such as convexity of order α (0 ≤ α < 1) and uniform convexity inside the unit disk, for a class of analytic functions related to the generalized Marcum... -
Estimates for the Pre-Schwarzian norm for certain subclasses of analytic functions
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Rashid Ali --- Government College University Faisalabad, Pakistan Mohsan Raza --- Government College University Faisalabad, PakistanFor λ ≥ 1, let be the class of analytic functions f in the open unit disc defined by . Similarly, for the class is defined by . In this article, we present estimates for the pre-Schwarzian norm of functions... -
One-sided Drazin invertibility in Banach algebras and perturbations of B-Fredholm spectra
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Kai Yan --- Fuzhou University, P.R. ChinaThe famous Drazin inverse and generalized Drazin inverse were originally introduced by Drazin in 1958 and Koliha in 1996, respectively. In this paper, the author presents simplified notions of left and right (generalized) Drazin inverses, which are the one-sided versions... -
Delta-shocks and vacuums as flux-approximation limit of solutions to the Aw-Rascle model with time-dependent source
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Mengqi Cui --- Department of Mathematics, Yunnan Normal University, P.R. China Shuai Fan --- Department of Mathematics, Yunnan Normal University, P.R. China Yu Zhang --- Department of Mathematics, Yunnan Normal University, P.R. ChinaThe flux-approximation limit of solutions to the Aw-Rascle (AR) traffic flow model with time-dependent source is considered. First, the Riemann problem containing flux perturbation and generalized Chaplygin gas (GCG) pressure is solved. Then, it is proved that, as the flux...